Kiwi plants in cultivation are mainly varieties of A. deliciosa, particularly ‘Hayward’ although some A. chinensis and A. arguta varieties are grown. A. deliciosa and A. chinensis are closely related and varieties of both types have large fruit (˜100 g) with hair on the skin. The main varieties in New Zealand are ‘Hayward’ (A. deliciosa) and ‘Hort16A’ (A. chinensis). Fruit are usually cut and eaten with a spoon.
All Actinidia species are dioecious, so female varieties have to be interplanted with male pollinizers to ensure fruit production.
A. chinensis vines are deciduous and tend to grow vigorously in spring and summer when rapidly-growing shoots can intertwine and tangle if not managed. Vines do best in a mild warm-temperate climate without late spring or early autumn frosts. They produce consistently heavy crops when grown in well-drained fertile soils and given regular irrigation in dry spells.
A. chinensis flowers in the spring (mid October-early December) in New Zealand. Harvest of A. chinensis fruit may occur between April and late-May in New Zealand depending on the selection and location of plantings.
Efficient pollination of female kiwifruit varieties influences seed numbers, which in turn influences fruit size and dry matter. In selecting new kiwifruit pollinizers the focus is on traits to enhance efficient pollination including pollen viability, pollen yield, number of flowers produced, and synchronization of the release of pollen from male flowers at the same time as the female flowers are receptive. A low vigor cultivar is preferred to minimize pruning costs.
The new variety was selected from a population of seedlings derived from a controlled pollination crossing of the kiwifruit varieties known as ‘Hort16A’ (U.S. Plant Pat. No. 11,066) and an unreleased selection CK39—16 (not patented) after observations of character and performance carried out from 1999 to 2000. The patented female parent ‘Hort16A’ was bred and selected in New Zealand, U.S. Plant Pat. No. 11,066. The unpatented male parent CK39—16 was selected in New Zealand from seedling plants raised from an introduction of open-pollinated seed from an un-patented parent from China in 1989. This new variety was created during the course of a planned plant-breeding program, which was initiated during 1995 in Te Puke, New Zealand. The cross was made on Oct. 29, 1995 in Te Puke, New Zealand. Seeds were sown in the spring of 1996 and 80 seedlings from this cross were planted out in the field at Te Puke in 1997. The selection ‘Bruce’ first flowered in October 2000. Selection ‘Bruce’ was grafted in 2000 onto five existing kiwifruit rootstocks at Te Puke, in a clonal selection trial plot, using graft wood from the original seedling plant.
The new variety was selected from among plants located on land at Te Puke, New Zealand, and was assigned the breeder code, 32-01-13a. The new variety has since been named ‘Bruce’.
The present invention is a new and distinctive kiwifruit male variety whose flowering period coincides well with the patented female kiwifruit plant ‘Hort16A’ in most districts where kiwifruit are grown in New Zealand.
The new variety can be asexually reproduced as cuttings or by grafting or budding on to seedling or cutting-grown rootstocks of A. deliciosa or A. chinensis. Trial plantings of grafted plants established at Te Puke, Nelson and Kerikeri in 2003 have shown that the unique combination of characters come true to form and are established and transmitted through succeeding asexual propagations.
The new variety is characterized as follows:    Plant ploidy: Diploid.    Plant form and vigor: A twining habit, with strong vigor, similar to ‘Hort16A’ (U.S. Plant Pat. No. 11,066); the surface of the dormant cane is smooth and a white bloom is present; distinctive red/brown hairs are evident on the young shoots and the underside of young leaves.    Foliage: The mature leaf is broad ovate in shape; the upper surface of the leaf is smooth; the lobes of a mature leaf are arranged slightly overlapping.    Flower: The number of flowers in each inflorescence is typically between one to four flowers, with each inflorescence comprising a single king flower and one or two side flowers; the single colored petal is absent of any red blotch which is sometime present on the petals of flowers of other male varieties, for example ‘Meteor’ (not patented).    Time of flowering: Early.    Plant health: No visible leaf symptoms have been observed indicating the plant is not virus-infected. Resistance to pests and disease is unknown.    Pollination efficiency: The new variety was initially selected on the basis of its potential for synchrony of flowering with the commercially important New Zealand female kiwifruit variety ‘Hort16A’ (U.S. Plant Pat. No. 11,066) and the resulting large fruit size of fruit of ‘Hort16A’ (U.S. Plant Pat. No. 11,066) after hand pollination with excess pollen. Subsequent trials indicate that flowering of the new variety does appear to be well synchronized with when female flowers of the variety ‘Hort16A’ (U.S. Plant Pat. No. 11,066) are receptive in many production areas in New Zealand. Observations of the performance of the new variety indicate it has potential to bring about improved yield from ‘Hort16A’ (U.S. Plant Pat. No. 11,066) relative to other male pollinizers currently used commercially in New Zealand such as ‘Meteor’ (not patented) and ‘Sparkler’ (not patented) due to better coincidence with ‘Hort16A’ (U.S. Plant Pat. No. 11,066) flowering, and good ability to influence fruit size when pollen is delivered to the female flowers. Key attributes of the new variety in this regard include good pollen viability, and a high pollen yield, in combination with a medium flower load per plant (measured as the number of flowers per meter cane).